Battery light comes on when i hit redline

[67Continental]

So last month I had the problem of my battery light coming on just before my car shifted at redline. I asked around, was told to check my tensioner. Sure enough, it was vibrating pretty bad at idle. So today I replaced my tensioner, idler pulley, and belt. And I still have the same problem. So, any ideas as to what this could be?

 

[poneyhexed]

At idle it is normal to see the tensioner bounce around allot or at the leased seam like allot.
When you rev the engine they usually smooth out as they take up the slack in the belt. I would suspect your alternator more than anything. Sometimes as the rectifier bridge starts to go bad you start see some strange things. Even as the brushes ware the spring tension on them become allot lighter. At the higher speed they even be lifting off the arburture and the car is seeing battery voltage(12.5) because the alternator cannot keep up. Has it ever been replaced and how many miles are on it ?? Even remove the belt and spin the alternator and listen. Does it sound like sand in a bearing or squeaking?? If so then of course the bearings are headed south to...

 

[67Continental]

the alternator has been replaced 6 times in the last 6 months, the one in the car is currently 3 weeks old. I am suspecting the alternator too

 

[98LSC32V]

You need to upgrade to an OEM 130amp 96-98 Mark VIII alternator. Much better than the old 120amp Mitisibishi one in the 93-95 Mark VIII.

 

[67Continental]

I don't have a 120 amp mitsubishi alternator - I have a 130 amp 6G alternator from Palladium, stock replacement for Continentals. Just seems like i keep getting bad ones.

 

[bufordtpisser]

6 alternators in 6 months................

the alternator has been replaced 6 times in the last 6 months, the one in the car is currently 3 weeks old. I am suspecting the alternator too

is very excessive. There has got to be another reason that your alternators keep going out. I am surprised that your parts guy is honoring the warranty after that many outages. I used to rebuild alternators, starters, and generators and never had 6 come back from any one customer in any amount of time.

 

[67Continental]

well, the part is from partsamerica and has a lifetime warranty, so they don't have a choice but to honour it. But I do agree with you that it is excessive - one of the alternators only lasted 6 days I wish I knew what the reason they keep dying is - so far, nothing seems to be an indicator.

 

[JMiles_T]

If you end up replacing the alternator again, replace the battery along with it. Make sure the new battery you get is fully charged before you start using it with the new alternator.

A dying battery can overwork a good alternator.

 

[67Continental]

I had the battery tested, and there were no issues with it - but if it does die again, I guess I will have no choice but to replace it as well

 

[Dr. Paul]

That seems really strange. Have you checked all of the various electrical connections in your charging system to verify continuity? Six alternators definitely seems excessive - I suspect another cause.

All engine grounds are sufficient and have good connections? A poor ground can cause some electrical mayhem.

Paul.

 

[MarkVIII93]

I just threw an 03' mach 1 alternator in and called it a day.

 

[1993_M75]

If you are seeing black dust around your alternator pulley, then you are experiencing belt slippage and should consider a Goodyear Gatorback belt.